uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Redox Behavior of Vanadium Oxide Nanotubes As Studied by X-ray Photoelectron Spectroscopy and Soft X-ray Absorption Spectroscopy
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry.
Show others and affiliations
2003 In: Chemistry of Materials, ISSN 0897-4756, Vol. 15, 3227-3232 p.Article in journal (Refereed) Published
Place, publisher, year, edition, pages
2003. Vol. 15, 3227-3232 p.
URN: urn:nbn:se:uu:diva-93254OAI: oai:DiVA.org:uu-93254DiVA: diva2:166682
Available from: 2005-09-08 Created: 2005-09-08Bibliographically approved
In thesis
1. Nanotubes for Battery Applications
Open this publication in new window or tab >>Nanotubes for Battery Applications
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanomaterials have attracted great interest in recent years, and are now also being considered for battery applications. Reducing the particle size of some electrode materials can increase battery performance considerably, especially with regard to capacity, power and rate capability. This thesis presents a study focused on the performance of such a material, vanadium oxide nanotubes, as cathode material for rechargeable lithium batteries.

These nanotubes were synthesized by a sol-gel process followed by hydrothermal treatment. They consist of vanadium oxide layers separated by structure-directing agents, normally amines or metal ions, e.g., Na+, Ca2+, Mn2+ and Cu2+. The layers are arranged in a scroll-like manner, allowing the interlayer structure to expand and contract, depending on the size of the embedded guest. This tubular form of vanadium oxide was able to insert lithium ions reversibly, making it a candidate cathode material. The structural and electrochemical response to lithium ion insertion was carefully studied to define optimal performance criteria and probe the lithium insertion mechanism. This was done using several characterization techniques, including X-ray diffraction, a variety of spectroscopic methods and electrochemical testing. Galvanostatic measurements show that the material can be charged and discharged reversibly for >100 cycles with a capacity of 150-200 mAh/g. The electrochemical performance is, however, dependent on the electrode film preparation technique, the choice of salt in the electrolyte and the nature of the embedded guest. Results from photoelectron spectroscopy, and soft X-ray emission and absorption spectroscopy confirm that vanadium is reduced during lithium insertion and that three oxidation states (V5+, V4+ and V3+) co-exist at potentials below 2.0 V. In situ X-ray diffraction, performed during potential stepping, identifies two separate processes during lithium insertion: a fast decrease of the interlayer distance followed by a slow two-dimensional relaxation of the vanadium oxide layers.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2005. 60 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 72
Inorganic chemistry, vanadium oxide, nanotubes, lithium battery, Li-ion battery, XRD, PES, electrochemistry, Oorganisk kemi
National Category
Inorganic Chemistry
urn:nbn:se:uu:diva-5870 (URN)91-554-6294-4 (ISBN)
Public defence
2005-09-30, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:15
Available from: 2005-09-08 Created: 2005-09-08Bibliographically approved

Open Access in DiVA

No full text

By organisation
Department of Materials Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 116 hits
ReferencesLink to record
Permanent link

Direct link